//点击菜单按钮出现又导航栏
let menuBtn = document.querySelector('.menubtn');
let subnav = document.querySelector('.subnav');
console.log(menuBtn, subnav);
menuBtn.onclick = function () {
  // subnav.style.display = 'flex';
  subnav.classList.toggle('active');
}
//点击关闭按钮关闭导航栏
let offbtn = document.querySelector('.offbtn');
offbtn.onclick = function () {
  subnav.classList.remove('active');
}
